JP3371916B2 - Epoxy resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel epoxy resin composition, and in particular, it has excellent heat resistance and high adhesiveness, as well as excellent moisture resistance, solder cracking resistance and stress resistance, and for laminates, An epoxy resin composition that can be used for semiconductor encapsulation, molding materials, adhesives, coatings, and the like.

[0002]

2. Description of the Related Art Heretofore, as an epoxy compound, an epi-bis type of diglycidyl ether of bisphenol A and a novolak type of diglycidyl ether of cresol novolak have been generally used.

Composite materials used for aircraft parts, and laminates, coating materials, semiconductor encapsulating materials, and molding materials in the field of electronics are generally obtained by using a polyfunctional epoxy resin having three or more functional groups. In general,
Mostly novolac type epoxy resin. Typical novolac type epoxy resins include phenol novolac type and cresol novolac type. Since the novolac type epoxy resin is polyfunctional, the crosslink density after curing becomes high, and as a result, high heat resistance and high chemical resistance can be expected, but on the other hand, it tends to be hard and brittle. Also,
Since the moisture resistance is poor and especially the adhesion to a metal is poor, the drawback that solder cracking is likely to occur due to humidity has been highlighted.

Copper-clad laminates are usually manufactured using a prepreg obtained by impregnating a reinforcing base material with a thermosetting resin as an insulating layer. In particular, glass-based epoxy resin copper-clad laminate,
It is mainly used for industrial electronic devices such as computers and control devices, and consumer electronic devices such as video cameras and video games. However, with the progress of high-density wiring circuits and multi-layers, the conventional glass-based epoxy resin copper-clad laminate cannot meet the requirements in terms of heat resistance, high adhesion, etc. There has been a demand for the development of a copper clad laminate having high adhesion and excellent moisture resistance.

[0005]

The present invention improves the heat resistance, which is a drawback of the conventional epi-bis type epoxy resin, of the above-mentioned novolac epoxy resin, but when used alone or epi-bis. When a large amount is mixed with the mold resin,
The delamination strength is lowered, the copper foil peel strength is lowered, and the moisture resistance is lowered. The present invention is intended to eliminate such drawbacks of epi-bis type and novolac type epoxy resins, and obtains a resin composition for lamination excellent in heat resistance, high adhesiveness and moisture resistance. This is the purpose.

[0006]

That is, the present invention is a thermosetting epoxy resin composition containing an epoxy resin and an aromatic hydrocarbon formaldehyde resin-modified novolac type epoxy resin, which comprises an epoxy resin and an aromatic hydrocarbon formaldehyde resin. 95% with modified novolac type epoxy resin
/ 5 to 30/70, the aromatic hydrocarbon formaldehyde resin-modified novolac type epoxy resin reacts with an aromatic hydrocarbon formaldehyde resin, phenol and formaldehyde to produce an aromatic hydrocarbon formaldehyde resin-modified novolac, This -OH group and epichlorohydrin are reacted to form glycidyl ether, and the number average molecular weight is 2,000 or less, preferably 1,500 or less, and the content of the monoglycidyl ether compound is 5% by weight or less. There is, the aromatic hydrocarbon formaldehyde resin used in the production of the aromatic hydrocarbon formaldehyde resin modified novolac type epoxy resin, number average molecular weight 300 ~ 1000, oxygen content 5 ~ 20%,
Melting point is in the range of 40 to 140 ° C., the aromatic hydrocarbon formaldehyde resin is one selected from the group consisting of mesitylene / formaldehyde resin, xylene / formaldehyde resin, toluene / formaldehyde resin and naphthalene / formaldehyde resin, or It is a mixture of two or more kinds, and the aromatic hydrocarbon formaldehyde resin-modified novolak is one produced by using aromatic hydrocarbon formaldehyde resin / phenol = 100/100 to 100/200 (weight ratio) Is a thermosetting epoxy resin composition.

The structure of the present invention will be described below. The present invention is characterized in that an aromatic hydrocarbon formaldehyde resin-modified novolac type epoxy resin is used, and this epoxy resin is usually obtained by reacting an aromatic hydrocarbon formaldehyde resin, phenol and formaldehyde. A hydrogen-formaldehyde resin-modified novolak is produced, and this -OH group is reacted with epichlorohydrin to form a glycidyl ether to produce the novolak. As the epoxy resin, in the present invention, the number average molecular weight is 2,0
00 or less, preferably 1,500 or less, particularly 800 to 1300, and the content of the monoglycidyl ether compound is 5% by weight.
Hereafter, it is particularly preferable to reduce the amount to 1% by weight or less.

If the number average molecular weight is more than 2,000, it is not preferable because the fluidity is deteriorated and the moldability is deteriorated. When the number average molecular weight is 400 or less, impact resistance, adhesiveness,
Moisture resistance is insufficiently improved. Further, if the content of the monoglycidyl ether compound is large, the working environment deteriorates and the heat resistance becomes insufficient.

The aromatic hydrocarbon formaldehyde resin as a raw material used for producing the aromatic hydrocarbon formaldehyde resin-modified novolac type epoxy resin of the present invention includes mesitylene, xylene, toluene, benzene, naphthalene, methylnaphthalene, dimethylnaphthalene, and others. Examples of the various aromatic hydrocarbons of 1 or a mixture of two or more of them are used as raw materials. Specifically, mesitylene-formaldehyde resin, xylene-formaldehyde resin, toluene-formaldehyde resin, benzene-formaldehyde resin, naphthalene- Formaldehyde resin and the like are exemplified.

As the phenol, phenol,
Examples include cresol, xylenol, resorcinol and the like. Any formaldehyde can be used as long as it generates formaldehyde under reaction conditions.
Furthermore, the method using epichlorohydrin is the most convenient and preferable for the reaction with the epoxy resin.

The aromatic hydrocarbon formaldehyde resin-modified novolak is the above-mentioned aromatic hydrocarbon formaldehyde resin and phenol, and inorganic acids such as sulfuric acid, hydrochloric acid and nitric acid, and acidic catalysts such as toluenesulfonic acid, xylenesulfonic acid and oxalic acid. After the reaction with, the acidic catalyst is further used, or a neutral catalyst such as calcium acetate, magnesium acetate, zinc acetate, other organic acid metal salt, zinc oxide is used to react with formaldehyde. To be Alternatively, a method of reacting phenols with formaldehyde and then reacting with an aromatic hydrocarbon formaldehyde resin or a method of simultaneously reacting an aromatic hydrocarbon formaldehyde resin, phenols and formaldehyde can be carried out. Incidentally, it is preferable not to use hexamethylenetetramine which is usually used as a curing agent.

Further, the ratio of the aromatic hydrocarbon formaldehyde resin to the phenols should be approximately equal to the reactive group equivalent of phenol which is usually used in the aromatic hydrocarbon formaldehyde resin used. Preferably, this reactive group includes, for example, -CH ₂ OH, -CH ₂ OCH _2- ,
-CH ₂ O -, - oxygen-containing groups such as CH ₂ OCH ₂ OH are exemplified. If the amount of phenol is too small, gelation etc. will occur in a part of the reaction product, resulting in increased viscosity and unreacted product remaining due to interruption of the reaction, and on the contrary, if it is too large, the plasticity will decrease. Adhesion is reduced. Further, formaldehyde is also set to such a degree as to cause a novolak reaction.

For example, when a xylene formaldehyde resin having a number average molecular weight of 350 to 800 and an oxygen content of 8 to 17% by weight is used and reacted with phenol, xylene formaldehyde resin / phenol = 100/100 to 100/250
(Weight ratio), preferably 100/10 to 100/200. The aromatic hydrocarbon formaldehyde resin novolak obtained by this method is usually a brown solid having a melting point of 60 to 120 ° C.

The phenolic hydroxyl group in the novolak modified with an aromatic hydrocarbon formaldehyde resin is reacted with epichlorohydrin and epoxidized to obtain a novolak epoxy resin modified with an aromatic hydrocarbon formaldehyde resin. The reaction can be carried out by a known method, and the obtained epoxy resin usually has a melting point of 45 ° C or higher.

The epoxy resin used as a mixture with the above-mentioned specific epoxy resin of the present invention is a known epoxy resin used for laminates, sealing, adhesives, paints, etc., and has been generally used conventionally. The present invention can be used without particular limitation. Examples thereof include glycidyl ether type such as bisphenol A type epoxy resin and phenol novolac type epoxy resin, glycidyl ester type, glycidyl amine type, linear aliphatic epoxide, and alicyclic epoxide. Further, these halogenated epoxy resins and the like can be mentioned, and among them, an epoxy resin having two or more epoxy groups in one molecule is preferable.

As the curing accelerator and catalyst, imidazoles, imidazolines, amines and the like generally used for epoxy resins may be used. Typical examples thereof include 2-ethyl-4-methylimidazole and 2,4,6-tris (diaminomethyl) phenol (abbreviation DMP-30). A novolac type phenolic resin is generally used as a curing agent for sealing. For laminated plates, dicyandiamide or the like is often used in combination with the above catalyst. An acid anhydride such as phthalic anhydride is generally used as a curing agent for casting and filament winding. As a curing agent for adhesives and anticorrosion paints, aromatic amines such as metaxylenediamine, aliphatic amines, polyamines and the like for low temperature curing are generally used.

In the case of producing laminated plates using the thermosetting epoxy resin composition of the present invention, as described above, the resin composition for lamination is applied or impregnated on a predetermined substrate and then dried. B-stage prepreg is manufactured by stacking a plurality of these prepregs, or by further stacking copper foils, and heating under pressure to manufacture. In this case, glass fiber cloth is generally used as the reinforcing base material, but in addition, aromatic polyamide fiber, aromatic polyester fiber, aromatic polyester imide fiber or the like can be used, and mat-shaped glass, polyester It is also possible to use aromatic polyamide, aromatic polyester fiber, aromatic polyesterimide fiber, and the like.

Application / impregnation of the reinforcing base material is performed under normal conditions,
Perform at room temperature to 60 ° C and dry at 100 to 180 ° C for 3 to 20 minutes to prepare a B-stage prepreg. Heating and pressurization is usually performed at a temperature of 120 to 230 ° C and a pressure of 5 to 150 kg / cm ² at 30 to 240.
Selected from minutes.

As the encapsulating resin, an inorganic filler such as silica, a release agent such as carnauba wax, a coupling agent such as epoxysilane, a flame retardant such as antimony trioxide and a halogen compound is usually selected according to the purpose of use. Then, in addition to the epoxy resin composition of the present invention, the mixture is heated and kneaded using a twin-screw kneader, a heat roll, a Hensyl mixer, and the like, and further, the obtained molding powder is tableted, etc., into a mold. By compression or transfer molding, 20-100 kg / cm ² , 150-200
After primary curing at ℃, post-curing at 180 ~ 230 ℃ for 2 ~ 12 hours. Further, the thermosetting epoxy resin composition of the present invention has excellent heat resistance, high adhesiveness, and moisture resistance,
It has plasticity at the time of heating, stress relaxation, etc., and furthermore, it is excellent in electrical performance, especially high frequency characteristics,
In addition to the above, it can be preferably used for adhesion and heat resistant coating.

[0020]

The present invention will be described with reference to the following examples. In the examples, "parts" and "%" are based on weight unless otherwise specified. Example 1 Xylene-formaldehyde resin (manufactured by Mitsubishi Gas Chemical Co., Inc., trade name; Nikanol G, number average molecular weight 520-620, oxygen content 14-16%) 100 parts and phenol 150 parts 0.1 parts paratoluenesulfonic acid It was used as a catalyst and reacted at 120 ° C. for 2 hours. Then, 1.5 parts of oxalic acid and 35 parts of 37% formalin were added and reacted at 100 ° C. for 3 hours. afterwards,
1.5 parts of slaked lime was added, and vacuum dehydration treatment was performed while heating. When the temperature reached 155 ° C, the vacuum dehydration was terminated and the melting point was 104 ° C
A xylene-formaldehyde resin-modified novolak phenol resin was obtained.

100 parts of this xylene-formaldehyde resin-modified novolak phenolic resin and 14 parts of solid sodium hydroxide were dissolved in 130 parts of water, while stirring vigorously.
Heated to 50 ° C. 32 parts of epichlorohydrin was mixed with stirring, and the temperature was kept at 80 ° C while stirring and mixing to carry out a uniform mixing reaction. After completion of the reaction, excess epichlorohydrin was removed under reduced pressure, and then benzene was added for washing to remove water. Purification was repeated by adding pure water again for washing and removing water. Then, it was distilled under reduced pressure to remove benzene, and the melting point was 83 ° C, the number average molecular weight was 1,220, and WPE 270 was used.
A xylene-formaldehyde resin-modified novolak epoxy resin (hereinafter referred to as "resin I") was obtained.

Brominated epoxy compound (manufactured by Tohto Kasei Co., Ltd.,
Part number; FX 132, epoxy equivalent 485 WPE) 70 parts were mixed with 30 parts of the resin I obtained above, 3.1 parts of dicyandiamide (abbreviation DICY) as a curing agent, and 2-ethyl-4-methylimidazole (abbreviation as a catalyst). 2E4MZ) 0.08 part, methyl ethyl ketone 32 parts as a solvent, dimethylformamide 8 parts to prepare a resin composition, glass cloth (# 7628-SV657,0.
2 mm thick) and dried in a dryer at 150 ° C. for 15 minutes to obtain a prepreg. 4 sheets of this prepreg are laminated, 18 μm and 35 μm double-sided roughened copper foils are laminated on both sides, and lamination molding is performed at a pressure of 80 kg / cm ² and a temperature of 170 ° C. for 90 minutes. I got a plate. The double-sided copper-clad laminate thus obtained was tested according to JIS S C-6481, K-6911, and the results are shown in Table 1.

Comparative Example 1 The procedure of Example 1 was repeated, except that the resin I of Example 1 was replaced with a bisphenol A type epoxy resin (trade name; Epicoat # 1001 manufactured by Yuka Shell Co., Ltd.). The results are shown in Table 1. Comparative Example 2 The procedure of Example 1 was repeated, except that the resin I of Example 1 was replaced with a cresol novolac type epoxy resin (#ESCN 220F manufactured by Sumitomo Chemical Co., Ltd.). The results are shown in Table 1.

Example 2 Xylene formaldehyde resin (manufactured by Mitsubishi Gas Chemical Co., Inc., trade name; Nikanol H, number average molecular weight 460-500, oxygen content 10-11%) 100 parts of phenol and 120 parts of paratoluene sulfonic acid 0.1 part was used as a catalyst and reacted at 130 ° C. for 2 hours. Then 1 part of zinc oxide and 37% formalin 50
And 100 parts of the mixture and reacted for 3 hours. Then, it was dehydrated under reduced pressure while heating, and when the temperature reached 150 ° C., the dehydration under reduced pressure was terminated to obtain a xylene formaldehyde resin-modified novolak phenol resin having a melting point of 102 ° C.

100 parts of this xylene-formaldehyde resin-modified novolak-phenolic resin and 13 parts of solid sodium hydroxide were dissolved in 130 parts of water and stirred vigorously.
Heated to 50 ° C. 32 parts of epichlorohydrin was mixed with stirring, and the temperature was kept at 80 ° C while stirring and mixing to carry out a uniform mixing reaction. After completion of the reaction, excess epichlorohydrin was removed under reduced pressure, and then benzene was added for washing to remove water. Purification was repeated by adding pure water again for washing and removing water. Then, it was distilled under reduced pressure to remove benzene, and the melting point was 85 ° C, the number average molecular weight was 1150, and WPE 265 was used.
A xylene-formaldehyde resin-modified novolak epoxy resin (hereinafter referred to as "resin II") was obtained. The same procedure as in Example 1 was carried out except that the resin II obtained above was used instead of the resin I. The results are shown in Table 1.

[0026]

[Table 1] Examples & Comparative Examples Real 1 Ratio 1 Ratio 2 Real 2 Glass transition temperature (DMA method) (℃) 171 150 172 168 Copper foil peel strength 35 μm (kg / cm) 1.93 2.00 1.78 2.10 18 μm (kg / cm ) 1.41 1.50 1.36 1.62 Delamination strength (kg / cm) 0.91 1.30 0.66 1.23 Volume resistivity (20 ℃) (× 10 ¹⁵ Ωcm) 8.0 7.0 3.0 8.0 Methylene chloride resistance Weight increase rate after 5 minutes 0.74 1.61 0.53 0.82 * 1 (%) 30 minutes later 1.85 2.20 1.89 1.88 Appearance 5 minutes later ○ ○ ○ ○ 30 minutes later ○ △ ○ ○ Moisture absorption heat resistance after 0 hours Moisture absorption% 0.82 0.88 0.88 0.81 * 2 〃 Appearance after solder float ○ △ ○ ○ Moisture absorption after 4 hours% 1.06 1.10 1.13 1.02 〃 Appearance after solder float × × × △ Moisture absorption after 5 hours% 1.14 1.18 1.26 1.08 〃 Appearance after solder float × × × × Flame retardant (UL 94) 94-V0 94-V0 94-V0 94-V0

* 1: After dipping in methylene chloride for a predetermined time, weigh and visually observe the appearance. ○: No change, △: slight surface roughness is observed. * 2: The test piece with the copper foil on both sides removed by etching
Treat with saturated water vapor at ℃ for a predetermined time, float it in a solder bath at 260 ℃ for 20 seconds and observe. ○: No change, △: Swelling is slightly observed. ×: There is swelling

Example 3 100 parts of naphthalene-formaldehyde resin and phenol
100 parts and 0.1 part of paratoluenesulfonic acid as a catalyst,
The reaction was carried out at 140 ° C for 2 hours. Then 1 part of oxalic acid and 37
% Formalin and 35 parts were added and reacted at 100 ° C. for 2.5 hours. Then, it is dehydrated under reduced pressure while heating, and the temperature is 165 ° C.
At this point, the dehydration under reduced pressure was terminated to obtain a naphthalene / formaldehyde resin-modified novolak / phenol resin having a melting point of 125 ° C. Other than using this naphthalene / formaldehyde resin-modified novolac / phenolic resin, the reaction, purification, etc. were carried out according to the method of Example 1, and the melting point was 114.
℃, epoxy equivalent 292WPE naphthalene-formaldehyde resin modified novolac epoxy resin (hereinafter "Resin II
I ").

Brominated phenol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product name; BREN, epoxy equivalent 2
85) 20 parts of resin III was mixed with 60 parts of resin III, and 41 parts of bisphenol A novolac (manufactured by Dainippon Ink and Co., product name; LF 7911) as a curing agent and 2,4,6-tris (diaminomethyl) as a curing accelerator. ) Phenol (abbreviation: DMP-30) (1 part) and carnauba wax (2 parts) as a release agent were mixed, and the binder was pulverized and mixed.

Further, as a coupling agent, 1 part of γ-glycidoxypropyltrimethoxysilane (manufactured by Nippon Unicar, product name; A-187), 1 part of carbon black as a coloring material, and antimony trioxide as a flame retardant aid. A filler consisting of 5 parts of powder and 350 parts of synthetic silica powder as a filler was mixed in a Hensyl mixer. Using the binder and the filler produced above, the mixture was roll-kneaded at 70 to 80 ° C. for 10 minutes, coarsely crushed, and then tableted to obtain a target resin composition for encapsulation for semiconductors. A cured resin test piece obtained by transfer molding this material into a mold equipped with an aluminum foil on the upper mold under the conditions of 180 ° C for 2 minutes and 70 kg / cm ² for workability during molding, heat resistance, and moisture resistance. And the presence or absence of cracks due to the heat and cold resistance cycle were tested. The results are shown in Table 2.

Example 4 40 parts of the same epoxy resin as that of Example 3 (manufactured by Nippon Kayaku Co., Ltd., product name; BREN, epoxy equivalent 285), 40 parts of resin I, 27 parts of curing agent LF 7911, and curing accelerator 1 part of DMP-30 and 2 parts of mold release agent carnauba wax were blended, and the binders were pulverized and mixed. Using the binder prepared above and the same filler as prepared in Example 3, at 70-80 ° C.
The mixture was roll-kneaded for 10 minutes, coarsely crushed, and then tabletted to obtain a target resin composition for sealing a semiconductor. This material is placed in a mold with aluminum foil on the upper mold at 180 ° C for 2
The cured resin test piece obtained by transfer molding under the conditions of 70 kg / cm ² was tested for workability during molding, heat resistance, moisture resistance, and the presence or absence of cracking due to cold / heat cycle. The results are shown in Table 2.

Comparative Example 3 Cresol novolac type epoxy resin (Sumitomo Chemical Co., Ltd.)
Product name: ESCN 195XL, epoxy equivalent 195) 65 parts, DMP-30 1 part as a curing agent, carnauba wax 2 parts as a release agent were mixed, and binders were crushed and mixed. Using the binder prepared above and the same filler as prepared in Example 3, roll kneading at 70 to 80 ° C. for 10 minutes, coarse pulverization, and tableting to obtain a target resin composition for encapsulation for semiconductors. Got A cured resin test piece obtained by transfer molding this material into a mold equipped with an aluminum foil on the upper mold under the conditions of 180 ° C for 2 minutes and 70 kg / cm ² for workability during molding, heat resistance, and moisture resistance. And the presence or absence of cracks due to the heat and cold resistance cycle were tested. The results are shown in Table 2.

[0033]

[Table 2] Examples & Comparative Examples Actual 3 Actual 4 Ratio 3 Glass transition temperature (DMA method) ℃ 173 167 165 20 μm thick aluminum foil Peel strength kg / cm 0.53 0.62 0.41 Bending strength kgf / mm ² 15.8 14.5 13.2 Bending elastic modulus kgf / mm ² 1450 1310 1630 Volume resistivity (20 ℃) × 10 ¹⁵ Ωcm 2.0 4.0 1.0 Moisture absorption heat resistance Moisture absorption after 10 hours% 0.27 0.29 0.39 * 3〃 Appearance after solder float ○ ○ ○ Moisture absorption after 20 hours% 1.06 1.10 1.13 〃 Appearance after solder float ○ ○ △ Flame retardance (UL 94) 94-V0 94-V0 94-V0 * 3: Treat the test piece from which aluminum foil was removed at 121 ° C in saturated steam for the specified time. , Float it in a solder bath at 260 ℃ for 20 seconds and observe. ○: No change. Δ: Swelling is slightly observed. ×: There is swelling.

[0034]

As is clear from the above detailed description of the invention and Examples, the epoxy resin composition of the present invention is
Obtain copper clad laminates, semiconductor encapsulants, adhesives, coating materials, and molding materials that have excellent heat resistance, low water absorption, solder crack resistance, and high adhesion, and have an excellent balance of properties. I was able to do something.

─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP-A-50-158694 (JP, A) JP-A-4-224825 (JP, A) JP-A-5-222148 (JP, A) JP-A-5- 295319 (JP, A) JP-A-6-157721 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 63/00-63/04 C08G 59/04-59/08

Claims (6)

(57) [Claims] 1. A thermosetting epoxy resin composition containing an epoxy resin and an aromatic hydrocarbon formaldehyde resin-modified novolac type epoxy resin. 2. The thermosetting epoxy resin composition according to claim 1, wherein the ratio of the epoxy resin to the aromatic hydrocarbon formaldehyde resin-modified novolac type epoxy resin in the epoxy resin composition is 95/5 to 30/70. object. 3. The aromatic hydrocarbon formaldehyde resin-modified novolac type epoxy resin is reacted with an aromatic hydrocarbon formaldehyde resin, phenol and formaldehyde to produce an aromatic hydrocarbon formaldehyde resin-modified novolac, and the -OH group It is obtained by reacting with epichlorohydrin to form a glycidyl ether, and has a number average molecular weight of 2,000 or less, preferably 1,500.
And the content of the monoglycidyl ether compound is
The thermosetting epoxy resin composition according to claim 1, which is 5% by weight or less. 4. The thermosetting epoxy resin according to claim 3, wherein the aromatic hydrocarbon formaldehyde resin has a number average molecular weight of 300 to 1000, an oxygen content of 5 to 20%, and a melting point of 40 to 140 ° C. Composition. 5. The aromatic hydrocarbon formaldehyde resin is one kind or a mixture of two or more kinds selected from the group consisting of mesitylene / formaldehyde resin, xylene / formaldehyde resin, toluene / formaldehyde resin and naphthalene / formaldehyde resin. Item 3
The thermosetting epoxy resin composition described. 6. The heat according to claim 3, wherein the aromatic hydrocarbon formaldehyde resin-modified novolac is produced by using aromatic hydrocarbon formaldehyde resin / phenol = 100/100 to 100/200 (weight ratio). Curable epoxy resin composition.